While lung simulators are known in the art, they are typically limited to devices suitable for cardiopulmonary resuscitation (CPR) training such as: U.S. Pat. Nos. 3,276,147 to de Bella, U.S. Pat. No. 4,001,950 to Blumensaadt, and U.S. Pat. No. 3,049,811 to Ruben. These patents illustrate the effect of mouth-to-mouth resuscitation upon one or more inflatable bags having some resistance to inflation and related operating equipment. Likewise, U.S. Pat. No. 3,274,705 to Breakspear illustrates a plurality of bags connected to inflate and deflate responsive to mount-to-mouth-resuscitation. None of these devices are suitable to demonstrate the interaction of the organs resident within a human thoracic cavity.
U.S. Pat. No. 4,167,070 to Orden (Orden) discloses an educational lung simulator having two single bladders, simulating left and right human lungs, within a self-supporting, transparent housing. The simulated left and right human lungs are suspended in spaces surrounded by a gas. On the contrary, human lungs are actually surrounded by a fluid. Four fixed-mass elements are mounted, one to each of a front face of one of the simulated lungs, two to inner surfaces of the simulated left and right lungs, and one to a single upper face of the other of the simulated lungs to exert “diverse pressures differing from one another” by positioning the simulator in different positions and orientations. However, close reading of Orden reveals that what is termed an “upper face 28 of lung 9a” is actually the lowermost tip of the simulated lung. This reversal of top and bottom is evident from FIG. 1 because the simulated esophagus 12 is located at the bottom of the FIGURE. Obviously, the fixed masses are not even symmetrical with respect to the two simulated lungs and, as demonstrated, weights are not accurately positioned. Therefore, it is clear that discrete fixed weights attached to the simulated, single bladder lungs provide only a very rough approximation of the complexities of the human lung system. Pressures within a pleural cavity surrounding the simulated left and right lungs are controlled by manually adjusting a bellows apparatus. Furthermore, there is no differentiation between the structure of the left and right simulated lungs as actually exists in a human.
Accordingly, what is needed in the art is a more accurate simulator of the human lung system with emphasis on presentation of the full range of lung maladies and injuries.